JP2016142805A - Optical apparatus, temperature detection method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical apparatus, a temperature detection method, and a program with which it is possible to reduce component counts, and in which the accuracy of detecting a temperature for temperature compensation is good.SOLUTION: A lens drive device 100 that is an example of an optical apparatus comprises: drive means for moving a lens N to a base 10; an optical sensor 40 having a light-emitting diode 41 and a phototransistor 42 for receiving light from the light-emitting diode 41 and outputting a signal corresponding to the received amount of light; control means for finding a position of the lens N in a direction of an optical axis C on the basis of the signal from the optical sensor 40; voltage acquisition means for finding a forward voltage of the light-emitting diode 41; and storage means for storing temperature characteristic data indicating a temperature characteristic of the forward voltage of the light-emitting diode 41. The control means finds an ambient temperature of the lens N on the basis of the forward voltage and the temperature characteristic obtained by the voltage acquisition means, as well as finding the position of the lens N.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical instrument, a temperature detection method, and a program.

  In optical devices such as cameras, movement control of optical members such as lenses is widely performed, for example, for a focusing operation. When the temperature of the optical member changes (for example, the focal length of the lens changes due to the temperature change), temperature compensation is required to maintain the performance of the optical apparatus.

  As an apparatus for performing such temperature compensation, Patent Document 1 discloses an optical apparatus provided with a temperature sensor for lens temperature compensation control. Patent Document 2 discloses a temperature detection device in which a transistor used for camera operation is also used for temperature detection.

JP 2007-6202 A JP 2001-337365 A

  As in the invention according to Patent Document 1, providing a dedicated temperature sensor leads to an increase in the number of parts. On the other hand, in the invention according to Patent Document 2, it is possible to reduce the number of parts by using a transistor used for camera operation also for temperature detection, but the transistor is separated from the optical member to be temperature-measured due to storage space restrictions. Since it may be disposed at a position, there is room for improvement in terms of improving the accuracy of temperature detection.

  The present invention has been made in view of the above circumstances, and relates to an optical apparatus, a temperature detection method, and a program that can reduce the number of components and have good temperature detection accuracy for temperature compensation.

In order to achieve the above object, an optical apparatus according to the first aspect of the present invention provides:
Drive means for moving the optical member relative to the base;
A light sensor comprising: a light emitting diode; and a light receiving element that receives light from the light emitting diode and outputs a signal corresponding to the amount of light received;
Control means for obtaining a position in the moving direction of the optical member based on the signal from the optical sensor;
Voltage obtaining means for obtaining a forward voltage of the light emitting diode;
Storage means for storing temperature characteristic data indicating a temperature characteristic of a forward voltage of the light emitting diode, and
The control means obtains the position, and obtains the ambient temperature of the optical member based on the forward voltage obtained by the voltage obtaining means and the temperature characteristic data.
It is characterized by that.

The storage means stores adjustment data for adjusting an output fluctuation amount accompanying a change in ambient temperature of the optical sensor,
The control means may adjust the output of the photosensor based on the obtained ambient temperature and the adjustment data.

The optical member includes a lens,
The drive means moves the lens in the optical axis direction of the lens,
The storage means stores correction data indicating a focal length change amount accompanying a change in ambient temperature of the lens,
The control means may correct a focal length change amount accompanying a change in the ambient temperature of the lens by moving the lens to the driving means based on the obtained ambient temperature and the correction data.

In order to achieve the above object, a temperature detection method according to a second aspect of the present invention includes:
Obtaining a position in the moving direction of the optical member based on a signal corresponding to the amount of received light output from the light receiving element that receives light from the light emitting diode;
Obtaining a forward voltage of the light emitting diode;
Obtaining the ambient temperature of the optical member based on the obtained forward voltage and temperature characteristic data indicating a temperature characteristic of the forward voltage of the light emitting diode determined in advance.
It is characterized by that.

In order to achieve the above object, a program according to the third aspect of the present invention provides:
On the computer,
Based on a signal corresponding to the amount of light received output from the light receiving element that receives light from the light emitting diode, a process for obtaining a position in the moving direction of the optical member;
A process for obtaining a forward voltage of the light emitting diode;
A process for determining the ambient temperature of the optical member based on the determined forward voltage and temperature characteristic data indicating a temperature characteristic of a predetermined forward voltage of the light emitting diode.
Is executed.

  According to the present invention, the number of parts can be reduced and the accuracy of temperature detection for temperature compensation is good.

1 is a schematic configuration diagram of a lens driving device according to a first embodiment of the present invention. It is a block diagram of the lens drive device concerning a 1st embodiment of the present invention. It is a principal part circuit diagram of the lens drive device concerning a 1st embodiment of the present invention. It is a flowchart of the temperature compensation process which concerns on 1st Embodiment of this invention. (A) is the figure of the table | surface which shows the relationship between the output voltage of an optical sensor, and the target distance of a lens, (b) is the figure which represented Fig.5 (a) with the graph. It is a figure which shows the relationship between the forward voltage of the light emitting diode of an optical sensor, and ambient temperature. (A) is the figure of the table | surface which shows the relationship between the ambient temperature of a lens, and a focal moving distance, (b) is the figure which represented Fig.7 (a) by the graph. (A) is the figure of the table | surface which shows the relationship between the ambient temperature of an optical sensor, and an adjustment value, (b) is the figure which represented Fig.8 (a) by the graph. It is a principal part circuit diagram of the lens drive device which concerns on 2nd Embodiment of this invention.

  An optical apparatus according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
The optical apparatus according to this embodiment is the lens driving device 100 shown in FIGS. 1 and 2. The lens driving device 100 is incorporated in, for example, an imaging device having an autofocus function, and moves the lens N in the direction of the optical axis C for focusing operation. The imaging device includes a digital camera (including a so-called compact digital camera), a portable terminal (including a smartphone) having an imaging function, a surveillance camera, and the like. In the following, first, the schematic configuration of the lens driving device 100 will be described with reference to FIGS. 1 and 2, and then the circuit configuration will be described with reference to FIG.

  As shown in FIGS. 1 and 2, the lens driving device 100 includes a base 10, a lens N, a lens driving mechanism 20, a motor 30, an optical sensor 40, a driving IC (Integrated Circuit) 50, and a storage unit. 60 and a control unit 70. As shown in FIG. 2, the drive IC 50 includes a motor driver 51 and a sensor amplifier 52.

  The base 10 includes a lens barrel that accommodates the lens N, and is formed so that the longitudinal direction of the lens barrel is along the optical axis C. The base 10 is provided with fixed lenses G1 and G2 so as to sandwich the lens N on the optical axis C.

  The light representing the subject passes through the fixed lens G1, the lens N, and the fixed lens G2 in this order, and is detected by the image sensor P. The image pickup device P is composed of an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary MOS) positioned on the optical axis C, and is disposed on a first circuit board B1 (printed circuit board) disposed in the base 10. Has been implemented. Note that the imaging device in which the lens driving device 100 is incorporated appropriately includes known configurations such as a diaphragm and an ND (Neutral Density) filter in addition to the imaging element P.

  The lens N is, for example, a focus lens composed of one or a plurality of lenses. The lens N is configured to be movable in the direction of the optical axis C by the lens driving mechanism 20 shown in FIG. The lens N is, for example, a plastic lens. Since the plastic lens has a relatively large linear expansion coefficient, the focal length is likely to change with respect to temperature change (see FIGS. 7A and 7B described later). In this respect, in order to maintain the performance of the optical device, it is necessary to perform temperature compensation as described later.

  The lens driving mechanism 20 includes a lens frame 21 (FIG. 1) that holds the lens N, a guide shaft (not shown) that guides the lens frame 21 in the direction of the optical axis C, and a gear mechanism that transmits the power of the motor 30 (see FIG. Not shown). The lens driving mechanism 20 moves the lens N in the direction of the optical axis C according to the rotation of the motor 30. A reflective portion 22 is formed in a portion of the lens frame 21 that faces the optical sensor 40.

  The motor 30 shown in FIG. 2 is composed of, for example, a stepping motor, and rotates by a drive signal supplied from the motor driver 51. The rotation of the motor 30 is transmitted to the lens N via the lens driving mechanism 20. Thereby, the lens N is movable in the direction of the optical axis C according to the rotation of the motor 30.

The optical sensor 40 is composed of, for example, a photo reflector, and includes a light emitting diode 41 and a phototransistor 42. The light emitting diode 41 irradiates light to the reflecting portion 22. The phototransistor 42 receives the light reflected by the reflecting unit 22 and outputs a signal (output voltage Vo) corresponding to the amount of received light to the sensor amplifier 52.
As shown in FIG. 1, the optical sensor 40 and the driving IC 50 are mounted on a second circuit board B <b> 2 (printed circuit board) disposed in the base 10. The second circuit board B2 is disposed opposite to the reflecting portion 22 in the left-right direction in FIG. The operation of the drive IC 50 will be described later.

  The storage unit 60 includes a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. In the ROM of the storage unit 60, an operation program for controlling the operation of each unit of the imaging device including the lens driving device 100, tables T1 to T4 described later, and the lens N associated with the distance to the subject are stored. Data such as a table indicating a focus position (hereinafter referred to as a focus position table) is stored.

The control unit 70 includes a CPU (Central Processing Unit) and the like, and executes an operation program stored in the storage unit 60 to control the operation of each unit of the imaging apparatus including the lens driving device 100.
For example, the control unit 70 drives and controls the motor 30 and the optical sensor 40 via the driving IC 50. In addition, the control unit 70 acquires a distance measurement signal indicating a distance from a distance sensor (not shown) to the subject, refers to a focus position table stored in the storage unit 60, and determines a lens corresponding to the distance to the subject. The focus position of N is obtained. That is, the control unit 70 cooperates with the distance measuring sensor to measure the distance to the subject, and realizes autofocus that automatically moves the lens N in order to perform focused imaging. For example, the distance measuring sensor includes a light emitting element that emits infrared light toward the subject, and a light receiving element that receives the infrared light reflected from the subject and outputs a distance measuring signal (for example, PSD (Position Sensitive Device)). ). In addition, the control unit 70 appropriately measures time with a built-in timer. Further, the control unit 70 executes a temperature compensation process unique to the present embodiment. This process will be described in detail later.

  Next, the circuit configuration of the lens driving device 100 will be described with reference to FIG.

(Circuit configuration)
The controller 70 is connected between the power supply line VDD and the ground line GND. Further, the control unit 70 communicates with the drive IC 50 via the bus.
The drive IC 50 includes a motor driver 51 that drives the motor 30 and a sensor amplifier 52 that includes a constant current circuit that performs light emission control of the light emitting diode 41. Operating power is supplied to the control unit 70 and the driving IC 50 from a power source (not shown) via the power line VDD.

  The motor driver 51 is configured by a switching circuit or the like provided corresponding to the coil of the motor 30. The motor driver 51 supplies a drive signal to the motor 30 under the control of the control unit 70.

The anode of the light emitting diode 41 is connected to the resistor R1, and the cathode is grounded. The sensor amplifier 52 is connected to the anode of the light emitting diode 41 via the resistor R1, generates a PWM (Pulse Width Modulation) signal with a variable duty ratio under the control of the control unit 70, and outputs the PWM signal to the resistor R1. As a result, the light emitting diode 41 is turned on / off by PWM control.
The anode of the light emitting diode 41 is connected to an A / D (Analog to Digital) port of the control unit 70 via a terminal Sf. The control unit 70 thus connected obtains the anode voltage of the light emitting diode 41 from the terminal Sf. Since the cathode of the light emitting diode 41 is grounded, the anode voltage obtained by the control unit 70 in this way is the voltage between the cathode and the anode of the light emitting diode 41 (forward voltage Vf). Based on the forward voltage Vf acquired in this way, the control unit 70 detects the ambient temperature of the optical sensor 40 as described later.

  The collector of the phototransistor 42 is connected to the power supply line VDD via the resistor R2, and the emitter is grounded. The collector of the phototransistor 42 is connected to the sensor amplifier 52 via the terminal So. The voltage Vo corresponding to the amount of light received by the phototransistor 42 is output from the terminal So to the sensor amplifier 52 thus connected. Then, the control unit 70 detects the position of the lens N in the optical axis C direction based on the data indicating the output voltage Vo acquired via the sensor amplifier 52.

  The position detection of the lens N by the control unit 70 is performed as follows. The output voltage Vo (V) of the optical sensor 40 and the movement distance (mm) of the lens N from a predetermined initial position shown in FIGS. It is done based on the relationship. FIG. 5 (a) shows the relationship in a table, and FIG. 5 (b) is a graph of FIG. 5 (a). This relationship is at a reference temperature (for example, 20 ° C.). In the storage unit 60, a movement distance detection table T1 set based on the relationship is stored in advance. The movement distance detection table T1 is data indicating the movement distance of the lens N (distance from the initial position of the lens N) associated with the output voltage Vo of the optical sensor 40.

  When performing the focus operation, first, the control unit 70 determines the focal position of the lens N (the initial position of the lens N) according to the distance to the subject based on the distance measurement signal from the distance sensor and the focus position table. Target distance from the position to the in-focus position). When the target distance is obtained, the control unit 70 rotates the motor 30 via the motor driver 51 and monitors the output voltage Vo of the optical sensor 40. Then, the control unit 70 stops the motor 30 when the output voltage Vo reaches a value corresponding to the target position based on the movement distance detection table T1. In this way, the lens N is moved to the in-focus position corresponding to the subject.

  At the reference temperature, the focusing operation is performed as described above. However, there is a problem in that the focal length of the lens N and the output of the optical sensor 40 change due to changes in the ambient temperature of the lens N and the optical sensor 40. Therefore, in order to maintain the performance of the imaging device including the lens driving device 100, temperature compensation in consideration of these changes is necessary. From here, the tables T2 to T4 necessary for temperature compensation will be described.

  First, the temperature characteristic table T2 for detecting the ambient temperature of the optical sensor 40 will be described. The temperature characteristic table T2 is set based on the temperature characteristic of the forward voltage Vf of the light emitting diode 41 shown in FIG. 6 (in the figure, the forward voltage shown on the vertical axis is the forward voltage, and the Ambient Temperature shown on the horizontal axis is the ambient temperature). ). As shown in FIG. 6, the forward voltage Vf and the ambient temperature of the light emitting diode 41 have a substantially proportional relationship, and the temperature characteristic table T2 is set using this characteristic. The temperature characteristic table T2 is data indicating the ambient temperature (° C.) of the optical sensor 40 (light emitting diode 41) associated with the forward voltage Vf (V). With reference to the temperature characteristic table T2 configured as described above, the control unit 70 detects the temperature according to the forward voltage Vf acquired as described above as the ambient temperature T of the optical sensor 40.

  Here, in the lens driving device 100 according to the present embodiment, in order to detect the position of the lens N in this way, the ambient temperature of the optical sensor 40 is detected using the optical sensor 40 disposed in the vicinity of the lens N. doing. Therefore, the ambient temperature of the optical sensor 40 detected by the control unit 70 based on the forward voltage Vf of the light emitting diode 41 can be regarded as the ambient temperature of the lens N. Therefore, in the following, the ambient temperature between the optical sensor 40 and the lens N will be simply referred to as “ambient temperature” without distinction.

  Subsequently, based on the ambient temperature detected in this way, the correction table T3 for correcting the focal length variation of the lens N due to the temperature change, and the adjustment for adjusting (correcting) the output variation of the optical sensor 40. The table T4 will be described.

The correction table T3 is set based on the relationship between the ambient temperature of the lens N and the focal distance as shown in FIGS. 7 (a) and 7 (b). FIG. 7 (a) shows the relationship in a table, and FIG. 7 (b) is a graph of FIG. 7 (a). As shown in FIG. 7B, the ambient temperature of the lens N and the focal distance due to the temperature change have a substantially proportional relationship, and the correction table T3 is set using this characteristic. The correction table T3 is data indicating the focal distance (mm) associated with the ambient temperature (° C.) of the lens N. Although FIGS. 7A and 7B show an example in which the reference temperature is 25 ° C., the reference temperature of the correction table T3 is actually combined with the reference temperature of the moving distance detection table T1 described above. It is preferable to set (the same applies to the adjustment table T4 described later).
With reference to the correction table T3 configured as described above, the control unit 70 calculates the focal distance (ie, the correction value for the focal fluctuation accompanying the temperature change) according to the ambient temperature T detected based on the forward voltage Vf. get.

  In the temperature detection method according to the present embodiment, the ambient temperature of the lens N and the optical sensor 40 can be detected well by using the optical sensor 40 disposed in the vicinity of the lens N for detecting the position of the lens N. . Conventionally, there has been a case in which the temperature sensor has to be disposed at a position away from the lens N due to storage space restrictions. Compared to this case, the temperature detection method according to the present embodiment has a temperature. The detection accuracy is good. Further, since it is not necessary to provide a dedicated temperature sensor, the number of parts of the lens driving device 100 can be reduced.

The adjustment table T4 is set based on the relationship between the ambient temperature (° C.) of the optical sensor 40 (light emitting diode 41) and the adjustment value (V) of the drive voltage shown in FIGS. 8 (a) and 8 (b). FIG. 8 (a) shows the relationship in a table, and FIG. 8 (b) is a graph of FIG. 8 (a).
The adjustment value of the drive voltage takes into account the characteristic that the ambient temperature of the light emitting diode 41 and the light emission amount are approximately proportional (the characteristic that the light emission amount decreases as the ambient temperature increases), and changes in the ambient temperature of the optical sensor 40. Is set as a value that compensates for the output fluctuation caused by. When the adjustment value is set in this way, the adjustment value and the ambient temperature of the light emitting diode 41 are also in a substantially proportional relationship as shown in FIG. Using this characteristic, an adjustment table T4 that is data indicating the adjustment value (V) of the drive voltage of the optical sensor 40 associated with the ambient temperature (° C.) of the light emitting diode 41 is set. The control unit 70 that has acquired the adjustment value corresponding to the detected ambient temperature based on the adjustment table T4 adjusts the duty ratio of the drive current via the sensor amplifier 52, so that the drive voltage at the reference temperature is obtained. A voltage to which the adjustment value is added is applied to the light emitting diode 41.

  Note that the control unit 70 may calculate an adjustment value from the detected ambient temperature by using a linear function obtained by linear approximation from the graph shown in FIG. For example, when the ambient temperature is X (° C.) and the adjustment value is Y (V), the linear approximation line can be expressed by the equation Y = αX + β (in the example of FIG. 8B, α≈0). .0167, β≈0.334), the control unit 70 may perform the calculation using the equation. In addition, the relationships shown in FIGS. 5B, 6 and 7B described above can also be considered as linear functions by linear approximation. Therefore, these relationships are similarly set in advance. The control unit 70 may perform calculation using an expression.

In the lens driving device 100 having the above configuration, for example, when the main switch of the imaging device is turned on and operating power is supplied to each unit, distance measurement, calculation of the focus position of the lens N according to the subject distance, and the like. Each of the processes is executed, and a temperature compensation process unique to the present embodiment is started.
From here, the temperature compensation process which the control part 70 of the lens drive device 100 performs is demonstrated with reference to the flowchart shown in FIG.

(Temperature compensation processing)
First, the controller 70 drives the optical sensor 40 (light emitting diode 41) via the sensor amplifier 52 (step S1), and waits for a predetermined time (for example, 10 ms) until the apparatus is in a steady state (step S2).

  Subsequently, the control unit 70 performs A / D conversion on the anode voltage of the light emitting diode 41 to obtain a digital value (step S3), and obtains the forward voltage Vf from the difference between the anode voltage and GND (step S4).

  Subsequently, the control unit 70 refers to the temperature characteristic table T2 stored in the storage unit 60, and uses the temperature corresponding to the forward voltage Vf acquired in step S4 as the ambient temperature of the optical sensor 40 (light emitting diode 41). It detects (step S5). Since the optical sensor 40 is provided in the vicinity of the lens N, the ambient temperature detected here can be regarded as the ambient temperature of the lens N.

Subsequently, the control unit 70 performs various temperature compensations based on the temperature detected in step S5 (step S6).
(1) Specifically, the control unit 70 refers to the adjustment table T4 stored in the storage unit 60, and acquires an adjustment value (V) corresponding to the detected ambient temperature T. Then, in order to realize the acquired adjustment value (V), the control unit 70 changes the duty ratio of the drive current supplied to the light emitting diode 41 via the sensor amplifier 52 to emit the drive voltage of the adjustment value. Applied to the diode 41. Thereby, the output fluctuation | variation accompanying the temperature change of the optical sensor 40 is adjusted, and the optical sensor 40 is temperature-compensated.
(2) In addition, the control unit 70 refers to the correction table T3 stored in the storage unit 60, and acquires the focal movement distance corresponding to the detected ambient temperature T. Then, the controller 70 adds (subtracts or subtracts) the focal distance acquired here to the distance (target distance) to which the lens N is driven and moved when performing the focus operation. Specifically, as described above, the control unit 70 determines the focal position of the lens N (from the initial position of the lens N to the in-focus position) according to the distance to the subject based on the distance measurement signal from the distance sensor. The target distance after correction is calculated by adding or subtracting the acquired focal distance to the target distance. Then, the control unit 70 stops the motor 30 when the output voltage Vo reaches a value corresponding to the corrected target position based on the movement distance detection table T1. As a result, the focal movement distance variation accompanying the temperature change of the lens N is adjusted, and the target position of the lens N is temperature compensated.
In step S5, the control unit 70 changes the temperature change amount (for example, the difference between a predetermined reference temperature and the detected ambient temperature, the ambient temperature detected in the previous process, and the ambient temperature detected in the current process). Or the like). And the control part 70 is good also as a structure which performs various temperature compensation according to the calculated | required amount of temperature changes.

  For example, the control unit 70 repeatedly performs the processes in steps S3 to S6 every predetermined period until the main switch of the imaging apparatus is turned off, and sequentially performs temperature compensation. The above is the temperature compensation process.

In the lens driving device 100 according to the first embodiment described above, as shown in FIG. 3, an example in which the resistor R1 is connected to the anode of the light emitting diode 41 and the resistor R2 is connected to the collector of the phototransistor 42 is shown. Not limited to.
Below, 2nd Embodiment which is an example of a circuit structure different from 1st Embodiment is described with reference to FIG. In the following, in order to facilitate understanding of the description, the same reference numerals as those of the first embodiment are used for the parts having the same functions as those of the first embodiment, and the description thereof is omitted, and different points are mainly described. .

(Second Embodiment)
In the lens driving device 200 according to the second embodiment, as shown in FIG. 9, the cathode of the light emitting diode 41 is grounded via a resistor R <b> 3 and the anode is connected to the sensor amplifier 52. The cathode of the light emitting diode 41 is connected to the A / D port of the control unit 70 via the terminal Sf. The control unit 70 connected in this way obtains the cathode voltage of the light emitting diode 41 from the terminal Sf.
The emitter of the phototransistor 42 is grounded via a resistor R4, and the collector is connected to the power supply line VDD. The emitter of the phototransistor 42 is connected to the sensor amplifier 52 via the terminal So. The voltage Vo corresponding to the amount of light received by the phototransistor 42 is output from the terminal So to the sensor amplifier 52 thus connected.

Even in such a circuit configuration, the control unit 70 executes a temperature compensation process similar to that of the first embodiment.
However, in the processing corresponding to steps S3 and S4 shown in FIG. 4, the control unit 70 of the lens driving device 200 according to the second embodiment performs A / D conversion on the cathode voltage of the light emitting diode 41 to obtain a digital value, The difference from the first embodiment is that the forward voltage Vf is obtained from the difference between the voltage and the cathode voltage. Other processes are the same as those in the first embodiment, and in the second embodiment, the output of the optical sensor 40 and the target position of the lens N are temperature-compensated.

The lens driving devices 100 and 200 as an example of the optical apparatus described above are driving means (the lens driving mechanism 20, the motor 30, the motor driver 51, etc.) that move the lens N (an example of an optical member) with respect to the base 10. A light sensor 41, a phototransistor 42 (an example of a light receiving element) that receives light from the light emitting diode 41 and outputs a signal corresponding to the amount of light received, and a signal from the light sensor 40. Based on the control means (control unit 70 and the like) for determining the position of the lens N in the moving direction, the voltage acquisition means (control unit 70 and the like) for determining the forward voltage Vf of the light emitting diode 41, and the forward voltage Vf of the light emitting diode 41. Storage means (such as the storage unit 70) for storing temperature characteristic data (for example, temperature characteristic table T2) indicating the temperature characteristics. The control means obtains the position of the lens N, and obtains the ambient temperature of the lens N based on the forward voltage Vf obtained by the voltage acquisition means and the temperature characteristic data.
According to this configuration, since the ambient temperature of the lens N is detected using the optical sensor 40 disposed in the vicinity of the lens N for detecting the position of the lens N, the temperature detection accuracy of the lens N is good. It is. In addition, since it is not necessary to provide a dedicated temperature sensor, the number of parts of the optical device can be reduced.

  In addition, this invention is not limited by said embodiment and drawing. Of course, it is possible to make appropriate changes (including deletion of components). An example of modification will be described below.

(Modification)
The optical device is not limited to the lens driving device 100 or the camera. Any optical device may be used as long as it drives an optical member such as the lens N. Further, the lens driving device 100 is not limited to one having an autofocus function, and may be one that manually performs a focusing operation according to a user operation.

  The lens N is not limited to the focus lens, and may be a zoom lens for zooming. The temperature detection method described above is suitable when the lens N is a plastic lens, but is not limited thereto. The lens N may be a glass lens. Furthermore, the optical member is not limited to the lens N, and may be the lens frame 21 or other parts as long as it is a member that is driven in a predetermined direction and that is thermally displaced and requires temperature compensation.

  In the above, an example in which the optical sensor 40 is configured with a photo reflector has been described, but the optical sensor 40 may be configured with a photo interrupter including a light emitting diode 41 and a photo transistor 42.

  The motor 30 is not limited to a stepping motor, and may be constituted by a DC (Direct-Current) motor, a voice coil motor, an ultrasonic motor, or the like.

  The operation program for executing each process described above is stored in the storage unit 60 in advance, but may be distributed and provided by a removable recording medium. In addition, the operation program may be downloaded from another device connected to the lens driving devices 100 and 200. In addition, the lens driving devices 100 and 200 may execute each process according to the operation program by exchanging various data with other devices via a telecommunication network or the like.

  In the above description, in order to facilitate the understanding of the present invention, the description of known unimportant technical matters is appropriately omitted.

DESCRIPTION OF SYMBOLS 100, 200 Lens drive device 10 Base N lens 20 Lens drive mechanism 30 Motor 40 Optical sensor 41 Light emitting diode 42 Phototransistor 50 Drive IC
51 Motor Driver 52 Sensor Amplifier 60 Storage Unit T1 Movement Distance Detection Table T2 Temperature Characteristic Table (Example of Temperature Characteristic Data)
T3 correction table (an example of correction data)
T4 adjustment table (example of adjustment data)
70 Control unit

Claims (5)

Drive means for moving the optical member relative to the base;
A light sensor comprising: a light emitting diode; and a light receiving element that receives light from the light emitting diode and outputs a signal corresponding to the amount of light received;
Control means for obtaining a position in the moving direction of the optical member based on the signal from the optical sensor;
Voltage obtaining means for obtaining a forward voltage of the light emitting diode;
Storage means for storing temperature characteristic data indicating a temperature characteristic of a forward voltage of the light emitting diode, and
The control means obtains the position, and obtains the ambient temperature of the optical member based on the forward voltage obtained by the voltage obtaining means and the temperature characteristic data.
An optical apparatus characterized by that. The storage means stores adjustment data for adjusting an output fluctuation amount accompanying a change in ambient temperature of the optical sensor,
The control means adjusts the output of the optical sensor based on the obtained ambient temperature and the adjustment data.
The optical apparatus according to claim 1. The optical member includes a lens,
The drive means moves the lens in the optical axis direction of the lens,
The storage means stores correction data indicating a focal length change amount accompanying a change in ambient temperature of the lens,
The control unit corrects a focal length change amount accompanying a change in the ambient temperature of the lens by moving the lens to the driving unit based on the obtained ambient temperature and the correction data.
The optical apparatus according to claim 1 or 2, wherein Obtaining a position in the moving direction of the optical member based on a signal corresponding to the amount of received light output from the light receiving element that receives light from the light emitting diode;
Obtaining a forward voltage of the light emitting diode;
Obtaining the ambient temperature of the optical member based on the obtained forward voltage and temperature characteristic data indicating a temperature characteristic of the forward voltage of the light emitting diode determined in advance.
The temperature detection method characterized by the above-mentioned. On the computer,
Based on a signal corresponding to the amount of light received output from the light receiving element that receives light from the light emitting diode, a process for obtaining a position in the moving direction of the optical member;
A process for obtaining a forward voltage of the light emitting diode;
A process for determining the ambient temperature of the optical member based on the determined forward voltage and temperature characteristic data indicating a temperature characteristic of a predetermined forward voltage of the light emitting diode.
A program that executes